A framework for the synthesis of multiphase reacting systems

2000 2000

Other formats: Order a copy

Abstract (summary)

A framework for synthesis, development, and design of reactors for multiphase reacting systems is presented. The reactor development begins in the laboratory, where the reaction is tested in micro- or bench scale reactors to identify systems which hold a potential for commercialization. The proposed systematic methods guide the user to consider key issues and phenomena that have to be considered at various scales, and the tools that can be invoked to tackle them.

For gas-liquid catalytic and non-catalytic reactions, the first step involves screening of various reactor types for the reaction under consideration, and identification of alternative designs as candidates for further studies. Special emphasis is placed on situations where there is a great deal of uncertainty regarding reaction kinetics, and little is known about potential limitations in heat and mass transfer. This procedure is then extended to tackle multiple reactions involving heat effects. Multiple reaction schemes are discussed, with the objective of maximizing the yield or selectivity of a desired product. The results of the screening procedure are used to propose a multiphase reactor network superstructure. Nonlinear programming is used to identify the optimum subset of the above superstructure for a specified reaction scheme and objective function.

Further reactor screening and development is illustrated for two- and three-phase fluidized bed catalytic reactors. A family of reactor models appropriate for particular reactor types and flow regimes is used to further tighten the performance estimates of the candidate reactors proposed in the earlier steps. Additionally, scale-up criteria are proposed to directly scale up the bench scale reactors to the commercial scale, while maintaining a similarity in some reactor performance index such as the conversion, the product yield or selectivity.

A similar approach is applied to the design of reactive crystallization and precipitation systems. The conventional equilibrium based design procedures are extended to incorporate the effects of mass transfer, and the kinetics of reaction, nucleation and crystal growth, by proposing a new, generic model. The reaction, mass transfer and dissolution Damkohler numbers, and the nucleation and growth numbers which result from the generic model, represent the relative rates of the individual steps, and their effect on the process paths, the resulting crystal size distribution and the crystallizer productivity is discussed for systems involving up to four components.

Indexing (details)

Chemical engineering
0542: Chemical engineering
Identifier / keyword
Applied sciences; Fluidized beds; Multiphase reactors; Reactive crystallization
A framework for the synthesis of multiphase reacting systems
Kelkar, Vaibhav V.
Number of pages
Publication year
Degree date
School code
DAI-B 61/09, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
9780599957442, 0599957441
Ng, Ka M.
University of Massachusetts Amherst
University location
United States -- Massachusetts
Source type
Dissertations & Theses
Document type
Dissertation/thesis number
ProQuest document ID
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
Access the complete full text

You can get the full text of this document if it is part of your institution's ProQuest subscription.

Try one of the following:

  • Connect to ProQuest through your library network and search for the document from there.
  • Request the document from your library.
  • Go to the ProQuest login page and enter a ProQuest or My Research username / password.